// <editor-fold defaultstate="collapsed" desc="GNU GPLv3 Header">
/*
 * File:   UlawDecoder.java
 *
 * Copyright (C) 2013 Robert Antoni Buj Gelonch <rbuj@uoc.edu>
 * Copyright (C) 2013 David Megias Jimenez <dmegias@uoc.edu>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
// </editor-fold>
package uoc.libcompression.G711;

/**
 * G711 U-Law Decoder.
 *
 * @author Robert Antoni Buj Gelonch <rbuj@uoc.edu>
 * @version 1.0
 * @since 2013-08-09
 */
public final class UlawDecoder extends Ulaw implements Decoder {

    /**
     *
     */
    public UlawDecoder() {
    }

    /**
     * Expands a compressed audio sample.
     *
     * @param sample The compressed data sample.
     * @return The expanded data sample.
     */
    public short expand(byte sample) {
        byte segment = (byte) ((sample & 0x70) >> 4);
        byte quant = (byte) (sample & 0x0F);
        int res = (0x10 | quant) << (segment + 1);
        return (short) Math.copySign(res, sample);
    }

    /**
     * Expands a compressed audio sample from a reception.
     *
     * @param sample The compressed sample that was recived.
     * @return The uncompressed data sample from a reception.
     */
    public short expandTransmission(byte sample) {
        return expand((byte) (~sample));
    }
}
